1. Field of the Invention
The present invention relates to a semiconductor production system for use in the production of semiconductor devices.
2. Description of the Related Art
In the production process of semiconductor devices, such as IC, LSI, and liquid crystal panels, substrates such as semiconductor wafer substrates and glass substrates are subjected to many working steps. Among these steps, an exposure step for patterning, and a resist-coating step and a development step performed before or after the exposure step, are important steps in the production process for semiconductor devices. Known apparatuses for performing these steps are exposure apparatuses such as steppers and scanners, and coater-developers.
These apparatuses are used alone in some cases; however, in recent years, these apparatuses have been primarily used in in-line systems which automatically perform a series of steps including coating, exposure, and development of a photosensitive resist on substrates. In the in-line system, an exposure apparatus and a coater-developer are connected in a line, and a robot delivers substrates between the exposure apparatus and the coater-developer.
In a conventional in-line system, a chamber containing the exposure apparatus and a chamber containing the coater-developer have openings at their adjacent walls, and substrates are delivered by a robot hand through the openings. Optical units including mirrors and lenses arranged in a light source device and an illumination optical system are degraded during long-term operation of the in-line system, and thus the performance of the system will be degraded due to a decrease in, or unevenness of, illuminance of the exposure light. Clouding is apparent on optical components which are arranged near positions having high optical energy, such as the illuminating section of the light source and collimated sections in the optical system.
As disclosed in Japanese Patent Laid-Open Nos. 4-128702 and 4-139453, a primary component causing such clouding is ammonium sulfate ((NH4)2SO4). Possible sources of the clouding are hexamethyldisilazane (HMDS) used as an adhesive promoter between a substrate and a resist, ammonia vapor released by concrete in the building, and sulfuric acid (H2SO4) used for stripping the resist on the substrate. Since HMDS is used in the coater of the in-line system, it is likely that HMDS vapor enters the exposure apparatus through the opening for delivering the substrate when the pressure in the coater is higher than that in the chamber containing the exposure apparatus.
Japanese Patent Laid-Open No. 7-130613 discloses a countermeasure to the problem of gaseous materials entering the chamber containing the exposure apparatus from an open air inlet port; however, it does not solve the problem of the diffusion of gaseous materials through openings for delivering substrates in an in-line system.
Accordingly, it is an object of the present invention to provide a semiconductor production system that solves the above-mentioned problems.
It is another object of the present invention to provide a semiconductor production system having an in-line subsystem including an exposure apparatus and a coater-developer, in which high-accuracy devices can be produced by reducing amounts of chemical substances leaked from the inline connecting section.
It is a further object of the present invention to provide a method for making a device using the above-mentioned system.
A first aspect of the present invention is a semiconductor production system including an exposure apparatus, a coater-developer, and an in-line subsystem for connecting the exposure apparatus and the coater-developer, the in-line subsystem including a removing unit for removing gaseous chemical substances entering from an in-line connecting section.
Preferably, the removing unit removes gaseous chemical substances entering the exposure apparatus from the in-line connecting section.
Preferably, a space shielded from the exterior of the semiconductor production system is provided at a substrate delivery channel between the exposure apparatus and the coater-developer.
The removing unit may have an evacuation means for evacuating the space. Alternatively, the removing unit may supply clean air through a chemical filter that removes the gaseous chemical substances.
Preferably, the semiconductor production system further includes a detecting unit for detecting the concentration of the gaseous chemical substances in the space. Preferably, the detecting unit detects at least one of ammonium ions (NH4+), sulfate ions (SO42xe2x88x92), and ammonia (NH3).
Preferably, the detecting unit detects the gaseous chemical substances by an ion chromatographic method, a diffusion scriber-type ion chromatographic method, or a coloring tape method.
Preferably, an automatically movable shutter or an air-curtain generating mechanism is provided between the space and the exposure apparatus and/or between the space and the coater-developer.
The space may be provided between the exposure apparatus and the coater-developer. Alternatively, the space may be provided in the exposure apparatus or in the coater-developer.
Preferably, the exposure apparatus is contained in a chamber, and has an air conditioning unit for controlling the temperature of the chamber.
Preferably, the exposure apparatus has an excimer laser light source.
A second aspect of the present invention is a method for making a device by the above-mentioned semiconductor production system.
Further objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings.